The present invention relates to office printers and more particular to an office printer that adjusts its throughput speed based on the amount of power necessary compared to the amount of power available.
Present office printer technology has come a long way from the days of impact printing. With the introduction of laser printing, one is able to make high resolution, permanent prints at reasonably fast speeds. The typical office is also increasing its requirements for performance, requiring faster and faster printing, with more and more options and capabilities.
As the progressive office user becomes more and more capable with the available technologies there is a tendency to complete complex printing jobs in the office instead of sending the jobs out to professional printing shops. This is for a variety of reasons, with convenience, timeliness, flexibility and cost being major contributors. With document media selection and finishing capabilities (such as stapling and binding), doing the job in the office can result in a professional-looking end product.
Imagine this possible scenario; the office professional wants to print and distribute packets of materials for an important proposal. The office professional knows that some of the data will not arrive from overseas until the morning of the presentation. For the proposal, the office professional needs letters, section separators, return labels and ballots (questionnaires for feedback on the presentation). The office professional knows that once the information arrives, the job must be completed quickly.
For some currently available high performance laser printers, this type of flexibility is not much of a problem. The printer automatically runs the job and adapts accordingly. For the letter, it pulls office letterhead from the heavy-bond drawer and prints it. Section separators likewise are selected from another input and run through the printer. The self-stick labels and ballot stock are pulled from other input sources. All of these media types have one thing in common, due to their heavy weight, rough surface or dense nature, they require additional heat from the fuser to melt and bond the toner when compared to regular office paper. On a long job, this situation becomes critical because this extra heat may be required faster than it can be supplied. In this particular situation, the printer has been programmed to change its throughput speed in order to retain acceptable fusing performance. Such a change in throughput speed can be accomplished by printing at the same speed, but allowing more time between printed pages or slowing the velocity the paper travels through the printer; either method, or a combination, may be referred to as changing the throughput speed of the printer. For the customer that is in a hurry, this may not be acceptable.
In other printers that may not be as sophisticated, the printer is not programmed to change throughput speeds to preserve overall finished-article quality, instead the printer loses fusing performance and print quality suffers. Examples of this may be smeared print, spots, blobs, streaks, and offsetting (recurring images at regular intervals). In cases where the toner is inadequately fused to the media, the printed image will not remain adhered to the media and may fall off, or may be rubbed or brushed off later. Other non-image related problems may occur if printer performance is exceeded. Media jamming, internal mechanism contamination, filter clogging and office environment contamination (dirty walls near the printer) due to the excessive loose toner in the printer may occur as well These items also have a negative effect on customer satisfaction.
There are limits to the amount of energy that can be safely drawn from a wall outlet. The power supply, circuitry and programming are all designed with safety and margins involved, which results in limiting printer operation to the lowest typically available power. Therefore, the maximum printer performance of the standard printer is limited by the typical power availability; for the United States, this is 110 VAC and 15 ampere service. With these limitations, the customer experiences their high performance printer reduced in performance equivalent to a medium performance printer. While this may be acceptable for some customers for a while, a busy office may demand high performance at all times especially from their network printer. Large offices may be able to afford replacing their printer with a commercial high volume printer as needed, however most customers will want to just have their standard office printer grow as their office requirements grow.
When an office originally purchases the printer, they may be on a limited budget but will want to purchase a printer that will grow as the office grows. Therefore they choose a basic, modular printer that they can immediately use and purchase additional capability as the office can afford them. In most cases, they will think only about their current printing and paper handling needs, especially if it is their first printer. In addition, they usually choose one that they can immediately plug in without doing any facilities changes.
As their office grows they eventually purchase all of the mechanical printer accessories that their jobs require. As their job capabilities, requirements and complexities grow, they find that their once high-performance printer becomes reduced in performance to a level that is significantly and noticeably degraded as described above.
Prior to the present invention, the user can not improve, or even regain, the printer""s performance. They are left with the choice of replacing what they have just paid to upgrade, or to just do without. If they replace the printer for a commercial unit, it likely to require heavier, more substantial power service. This, along with the cost of the commercial printer, is a significant expense.
There is provided an imaging device having multiple throughput speeds of operation. To accomplish the invention there is a universal power supply connected to an external power source. An input power sensor is attached to the universal power supply. The input power sensor generates a power signal indicative of an amount of power available from the external power source. A controller receives the power signal and monitors power requirements of the imaging device. The controller selects the highest throughput speed of safe operation based on the power available and the power needed to operate at that speed.
There is also provided a method for operating an imaging device. An amount of available power is determined, based primarily on the voltage of the power source. The imaging device configuration is determined. A maximum throughput speed at which the imaging device can operate is calculated, where the maximum throughput speed is dependent on the amount of available power and the imaging device configuration. The imaging device is then limited to operating no faster then the maximum throughput speed calculated.